CHAPTER 5: OPPORTUNITIES AND CONSTRAINTS Flashcards
(59 cards)
What are some conditions and considerations that shape site constraints and opportunities?
Conditions include:
* Lot size and shape
* Historic structures and views
* Significant vegetation
* Hydrology
* Geology and soils
* Topography
* Climactic conditions
* Wildfires
* Wildlife habitat
* Noise and nuisances
These factors significantly influence site development decisions.
What might be a site constraint for constructing a 100,000 sf distribution center?
Constraints include:
* Steep slopes requiring excavation
* Lack of access to highways or rail
* Local opposition to construction
Site constraints often hinder development processes.
What is a watershed?
A watershed is a land area that contributes surface water to a location, defined by surface topography.
Watershed boundaries occur along ridges.
Define ‘time of concentration’ in hydrology.
Time of concentration refers to the amount of time needed for water to flow from the most remote point in a watershed to the watershed outlet.
It is dependent on slope, surface, and channel characteristics.
What is evapotranspiration?
Evapotranspiration is the process where water is transferred from land and water surfaces to the atmosphere, with plants contributing to the process.
It can recycle up to 50% of precipitation back to the atmosphere.
Describe surface runoff.
Surface runoff is precipitation that flows off the land surface downhill.
It is influenced by precipitation, soil type, slope, and vegetation.
What does groundwater refer to?
Groundwater is subsurface water flow that discharges to streams, lakes, wetlands, or the ocean, known as ‘base flow’ under normal conditions.
Groundwater plays a crucial role in hydrology.
What is a riparian corridor?
A riparian corridor is the area that encompasses a river or stream and the adjacent land.
Erosion occurs on the outside bank, while sediment deposition occurs on the inside bank.
What is the significance of water table depth in development?
Water table depth can prevent site drainage, complicate excavation, and preclude the use of septic systems.
It also requires waterproofing for building foundations.
What is a floodplain?
A floodplain is an area of land adjoining a body of water that may be covered by floodwater.
Floodplains act as pressure relief valves for floodwaters.
What is a 100-year floodplain?
A 100-year floodplain has a 1% chance of flooding in any given year.
New developments can increase flood risks.
What are floodplain areas composed of?
Floodplain areas consist of:
* Channel
* Floodway
* Flood fringe
Each area serves a different function during flooding.
Define Base Flood Elevation (BFE).
Base Flood Elevation (BFE) is the elevation of the 100-year floodplain studied in detail, used to determine safe construction heights.
Freeboard is the height of floodwater above the BFE.
What are hard engineering structures in flood management?
Hard engineering structures include levees and riprap.
These can increase streambank erosion.
List methods to mitigate flood hazards.
Methods include:
* Expanding stormwater infiltration
* Minimizing impervious surfaces
* Decreasing runoff volume
* Restricting development in floodplains
* Using green infrastructure
Green infrastructure can slow water velocities.
What are the components of soil?
Soil is composed of:
* Sand
* Silt
* Clay
Soil composition affects its characteristics and suitability for development.
What is soil infiltration rate?
Soil infiltration rate is the speed at which water flows into soil through small pores.
It is crucial for stormwater management.
What risks are associated with expansive soils?
Risks include:
* Ground heave
* Liquefaction
* Differential subsidence
* Settlement
* Landslides
Expansive soils can cause significant structural issues.
What is differential subsidence?
Differential subsidence occurs when soil beneath a building sinks at different rates, leading to instability.
This can happen when structures cross different soil profiles.
What is the impact of bedrock on site development?
Presence of bedrock increases development costs and complicates excavation.
Excavation activities should avoid areas where bedrock is present.
What factors exacerbate earthquake damage?
Factors include:
* Building height
* Proximity to fault lines
* Hillside location
* Orientation of structures to seismic activity
Taller buildings are more susceptible to damage.
How does topography affect site planning?
Topography influences building location, road alignments, pedestrian circulation, and stormwater management.
Grading can cause significant site disturbances.
Define microclimates.
Microclimates are site variations due to changes in topography, vegetation, and orientation.
They can significantly affect climate conditions on a site.
What are design considerations for hot/arid sites?
Considerations include:
* Avoid heat-absorbing materials
* Create favorable microclimates with walls
* Deflect hot winds
* Use drought-tolerant plants
These help manage heat and water use.
